DIFFERENTIAL AMPLIFIER WITH INCREASED INPUT RESISTANCE Russian patent published in 2011 - IPC H03F3/45 

FIELD: radio engineering.

SUBSTANCE: differential amplifier (DA) with increased input resistance includes the first and the second input transistors (T) (1, 2) the bases of which are connected to the first and the second inputs (3, 4) of DA, and collectors are connected to the first and the second current outputs (5, 6), the first and the second auxiliary T (7, 8) the bases of which are connected to the appropriate bases of the first and the second T (1, 2), collector of the first T (7) is connected to collector of the second T (2), collector of the second T (8) is connected to collector of the first T (1), differential circuit (DC) of setting the static mode with the first and the second outputs (10, 11) and common output (12) connected to power supply bus (13). To the scheme there introduced is the first and the second current mirrors (CM) (14, 15), the input of CM (14) is connected to emitter of T (1), input of CM (15) is connected to emitter of T (2), output of CM (14) is connected to emitter of T (8), output of CM (15) is connected to emitter of T (7), emitter output of the first CM (14) is connected to the first output (10) of DC, and emitter output of CM (15) is connected to the second output (11) of DC.

EFFECT: increasing R_in by one or two orders without deterioration of energy parametres in static mode.

11 dwg